Drug Interaction Report

Some of the medication in prilocaine topical is absorbed through the skin into the bloodstream and may cause interactions with other medications such as lidocaine topical. When used together, this combination may increase the risk of methemoglobinemia, a condition that can lead to oxygen deprivation in tissues and vital organs due to reduced oxygen-carrying capacity of the blood. Individuals may be more susceptible to developing methemoglobinemia during treatment with these medications if they are very young (especially neonates and infants) or have anemia, diseases of the heart or lungs, blood circulation disorders, liver cirrhosis, shock, sepsis, and certain genetic predispositions such as NADH cytochrome-b5 reductase deficiency, glucose-6-phosphate dehydrogenase deficiency, and hemoglobin M. In addition, excessive use of prilocaine topical such as application of large doses or on larger than recommended areas, as well as use on inflamed or abraded areas or broken skin, can increase absorption and result in high blood levels of the medication. Close medical supervision is necessary when medications that can cause methemoglobinemia are used together. Signs and symptoms of methemoglobinemia may be delayed by several hours after treatment with prilocaine topical. Patients (or their caregivers) should seek immediate medical attention if they develop a gray discoloration of the skin, mouth, or nail bed; nausea; headache; dizziness; lightheadedness; fatigue; shortness of breath; rapid or shallow breathing; a rapid heartbeat; palpitation; anxiety; or confusion. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Products containing folic acid may increase the effects of fluorouracil. You may be more likely to develop serious side effects such as anemia, bleeding problems, infections, and nerve damage when these medications are used together. Contact your doctor if you experience severe nausea and vomiting, diarrhea, paleness of skin, fatigue, dizziness, fainting, unusual bleeding or bruising, blood in the stools, fever, chills, body aches, flu-like symptoms, skin reactions, mouth ulcers or sores, and/or numbness, burning or tingling in your hands and feet. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.